Fruit Thinning Organic

Depending on market requirements and in years of heavy fruit set, both apples and pears may require thinning to achieve good fruit size and regulate crop load, reducing the risk of biennial bearing. Although laborious, hand- thinning is the most reliable method and affords the grower the opportunity to inspect the crop carefully, both in terms of assessing yield and also inspecting the trees for pest and disease problems. Apples and pears should be hand- thinned after the natural 'June drop' from mid-June to the end of July, although apples should preferably be thinned before they reach 12rnm in diameter. When thinning, take off small or poor-quality fruits first and those that are shaded or on weak or one-year-old wood before thinning remaining clusters. It is advisable to thin to one or two fruits per cluster, ensuring fruits are spaced 10mm apart. On short-stalked apples, the 'king' fruit should be removed (this is generally the largest fruit and is often misshapen), leaving the next largest intact. King fruits of long-stalked varieties can be retained to crop since they are usually of good size and not misshapen.

Most varieties of apple and pear ripen in September and October, although early varieties such as Discovery require picking in August for immediate marketing (most early varieties will not store well). Storage is otherwise usually required to avoid flooding the market at harvest time and top fruit growers either have their own stores or hire storage space. For most small-scale operations, refrigerated storage will be sufficient to keep fruit in good condition for the few weeks needed, as most organic top fruit is sold off the farm by November or December. However, for growers requiring longer term storage, particularly those supplying supermarkets, the use of CA regimes is required.

It is important that the fruit is picked at the correct stage of maturity for the proposed marketing period, if it is to be stored for any length of time. Levels of starch and fruit firmness should be assessed at regular intervals, together with fruit mineral composition, starting at least a month before the anticipated harvest date. Growers may monitor their crops themselves, but may wish to employ the services of an adviser for expert guidance and access to analytical services. Greater firmness and starch levels will be required for fruit entering long-term storage, which will therefore require earlier picking. CA and ULO regimes are best used for apples destined for marketing after the middle of October, otherwise low-temperature basic air storage is sufficient for most varieties, including pears.

More details on specific storage requirements for apple varieties, together with other recommendations for storing fruits, can be found in Guidelines for the Production of Organic Apples and Pears in the UK, published by the Soil Association.